NAME¶
CheckDigits::MXX_006 - compute check digits with Verhoeff scheme
SYNOPSIS¶
use Algorithm::CheckDigits;
$verhoeff = CheckDigits('verhoeff');
if ($verhoeff->is_valid('14567894')) {
# do something
}
$cn = $verhoeff->complete('1456789');
# $cn = '14567894'
$cd = $verhoeff->checkdigit('14567894');
# $cd = '4'
$bn = $verhoeff->basenumber('14567894');
# $bn = '1456789'
DESCRIPTION¶
ALGORITHM¶
- 1.
- Right to left all digits are permutated according to a permutation
table.
- 2.
- The permutated digits are combined using a dieeder table. The first with
the second, the result with the third, this result with the fourth and so
on.
- 3.
- The result of the last combination in the dieeder table is in such a way
combined that the result is 0 (zero). The number used for this combination
is the checksum.
For details look at the source.
METHODS¶
- is_valid($number)
- Returns true only if $number consists solely of numbers and the last digit
is a valid check digit according to the algorithm given above.
Returns false otherwise,
- complete($number)
- The check digit for $number is computed and concatenated to the end of
$number.
Returns the complete number with check digit or '' if $number does not
consist solely of digits.
- basenumber($number)
- Returns the basenumber of $number if $number has a valid check digit.
Return '' otherwise.
- checkdigit($number)
- Returns the checkdigit of $number if $number has a valid check digit.
Return '' otherwise.
EXPORT¶
None by default.
AUTHOR¶
Mathias Weidner, <mathias@weidner.in-bad-schmiedeberg.de>
THANKS¶
Jonathan Peters wrote Algorithm::Verhoeff from which I took the routine to
compute the checkdigits.
SEE ALSO¶
perl, CheckDigits, <
http://www.cs.utsa.edu/~wagner/laws/verhoeff.html>,
<
http://www.cs.nmsu.edu/~cssem/Dickcheckdoc.pdf>